configure: stop AC_SUBST'ing ODP_ABI_COMPAT

With static_inline.h gone, there is no need to
AC_SUBST([ODP_ABI_COMPAT]). Drop it from configure.ac.

Signed-off-by: Dmitry Eremin-Solenikov <dmitry.ereminsolenikov@linaro.org>

configure.ac

@@ -270,7 +270,6 @@ AC_ARG_ENABLE([abi-compat],
 	#if there is no ABI compatibility the .so numbers are meaningless
 	ODP_LIBSO_VERSION=0:0:0
     fi])
-AC_SUBST(ODP_ABI_COMPAT)
 AM_CONDITIONAL(ODP_ABI_COMPAT, [test "x$ODP_ABI_COMPAT" = "x1"])
 
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